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(No Model.)

E. G. PARKHURST FRIGTION H'OLDPAST.

No. 341,500. Patented May 11, 1886.v

UNITED STATES PATENT EDVARD G. PARKHURST, OF HARTFORD, CONNECTICUT,ASSIGNOIL TO THE PRATT 8: NVHITNEY COMPANY, OF SAME PLACE. l

FRlCTlON-HOLDFAST.

SPECEFICATION forming para of Letters Patent No. 341,500, dated May11,1886.

- Application tiled October 29, 1885. Serial No. 131,209. (No model.)

To aZZ whom it may concern.-

Be it known that I, EDWARD Cr. PARK- HURsT, a citizen of the UnitedStates, residing at Hartford, in the county of Hartford. State ofConnecticut, have invented certain new and useful Improvements inFriction-Holdfasts, of which the following` is a specification.

This invention relates to improvements in holdfasts for securing in anyposition within a specified amplitude the swinging` part ot' amachine-gun mount, or of other similarly operated parts.

The object of the invention is to provide a powerful and compactapparatus operating by friction, and which may be operated from thelever whereby the swinging part is operated.

To this end the invention consists in the devices andcombinationshereinafter set forth.

In the drawings accompanying and forming a part of this specification,Figure 1 is a side elevation of an apparatus embodying my invention.Fig. 2 is a vertical longitudinal section of the same. Fig. 3 is avertical transverse section in line a a, Fig. 2. Fig. 4 is a perspectiveview of the wedge-ring. Fig. 5 is a perspective view of one of the twosimilar friction-plates.

Similar characters designate like parts in all the iigures.

Any suitable base, A, varying in construction according to the situationin which the holdfast is to be applied, has rising therefrom two sidewalls, B B, which walls stand parallel to each other, and are preventedfrom spreading by the strong'bolt N, having a head, 2, and a nut. 3, ofthe usual description.

Closely iitting between walls B B are the two similar parallel walls C Cof the swinging frame F, which is pivoted on bolt N.

Between walls C C, and closely fitting bolt N, are placed, opposite toeach other, two similar beveled-edge friction-plates, P, which areprevented from turning `by a pin, 4, that fits closely in the holes 5,Fig. 5, in said plates, and is firmly driven into other holes in walls BB. This is shown best in Fig. 3. Said pin passes through slots in wallsC C, so

that frame F is not thereby prevented from swinging through These slotsare indicated by a dot-ted line at (i, Fig. 2.

The wedge'ring is designated by R, and is divided on one side at 7, oneither side of which cut the ring has lugs S and 9. One ot' 55 saidlugs, 8, is threaded to receive the correspendiugly-threaded end Il()ot' shaft S, the other being bored, as at l1, Fig. 4. Said shaft has abearing at l2 in the outer end of frame F, and is provided with ahandle-ais, for in 6o stance, H-whereby it is operated, and has ashoulder at 13, bearing against lug 9. On turning the shaft over towardthe righthand (when the thread on it is right-handed) the lugs are drawntogether, thereby closing up the wedge-ring, and `forcing plates P apartand against walls C C, which in turn are sprung slightly apart firmlyagainst walls B B. Thus by a single operation ofthe shaft are all theparts arranged about the bolt N 7o strongly clamped into one firm mass.On unscrewing the shaft S the ring R is allowed to expand by reason ofits own elasticity. The plates and walls are thereby freed, and theframe F may then be swung up or down at will by means of the same shaftused as a lever therefor. By means of this construction' the swingingframe may be instantly clamped and unclamped, and very quickly changedfrom one posit-ion to another without letting 8o go of the handle.

Having thus described my invention, T claiml.. The combination, in africtiou-holdfast, of a base having a pair of parallel walls, a swingingframe having parallel walls fitting within .the base-walls, a pair ofbeveled oppositely-disposed friction-plates fitting between theframe-walls, a wedge-ring inelosing and operating to force apart saidplates, a bolt 9o passing through said plates, frame-walls, andbase-walls, and a shaft operating to close and unclose said ring,substantially as set forth, and for the purpose specified.

2. The combination, in a friction-holdfast, of a base having walls B B,a frame having the required distaneep5o' walls C C, plates P P, bolt N,'andpin 4, and

S, operating as a lever to swing the frame, and a Wedge, substantiallyas described, forcing as a shaft to clamp and unclamp said appa- 1oapart said plates, substantiallyfas set forth. ratns, substantially asset forth.

3. The combination in a friction-holdfast s Y 5 ofa base having wallsBB, a swinging frame EDWARD G' PAR'KHURST' having walls C C, and a.bearing at 12 for Witnesses: shaft S, a friction apparatus,substantially as GEO. A. REYNOLDS, described, between Walls C C, and ashaft, as I F. H. RICHARDS.

